Industrial-scale catalytic as phase oxidation reaction generally uses a fixed-bed reactor in which a starting compound-containing gas is made to pass through a reaction tube filled with catalyst, and is thus allowed to react. In particular for the production of (meth)acrolein and (meth)acrylic acid by catalytic gas-phase oxidation reaction of propylene, propane, isobutylene, etc., as a raw material compound, there has widely been employed a catalytic gas-phase oxidation reaction with a fixed bed multitubular reactor which is filled with solid particulate heterogeneous catalyst. Solid particulate heterogeneous catalyst which is to be used for this purpose generally includes a molded catalyst (unsupported catalyst) which is composed of active ingredients which have been molded into a specific geometric shape and a supported catalyst which is composed of a carrier material which has a geometric shape like that of molded catalyst and which has been coated with active ingredients (Patent Document 1).
There have been proposed methods for producing acrolein and acrylic acid with a high yield by catalytic gas-phase oxidation reaction of propylene, with a fixed-bed multitubular reactor which is filled with solid particulate heterogeneous catalyst as mentioned above. Most of such proposals relate to molybdenum-bismuth catalysts each of which mainly comprises molybdenum and bismuth which are used in the above-mentioned reaction, in detail to the composition, shape, physical properties of the catalysts and how to produce the same (Patent Documents 2, 3, and the like). There have also been made some proposals which relate to how to fill reaction tubes of a fixed-bed multitubular reactor with catalyst (Patent Documents 4, 5, 6 and 7).